Mediation of compensatory renal growth in the rat: cell culture demonstration of a serum factor.

Abstract

1. The participation ofa circulating growth factor in the mediation ofcompensatory renal growth has been hypothesized but not proven. Theoretical considerations predict that in vitro methods could be profitably used to resolve this question, since such methods would allow dissociation of the growth effects of the postulated factor from the complex physiological changes which accompany compensatory renal growth in vivo.2. A culture system using epithelial cells obtained from the rat kidney is described which is suitable for testing serum from previously unilaterally nephrectomized or sham-operated rats for the presence ofa factor mediating compensatory renal growth. The morphology of the cultured cells is compatible with that of proximal tubule epithelium, this being the cell type stimulated to divide in vivo after unilateral nephrectomy.3. Treatment with serum from rats unilaterally nephrectomized 48 h previously results in consistent increase in uptake of tritiated thymidine by cultures, when compared with control serum from sham-operated rats. Serum from rats unilaterally nephrectomized 18-36 h previously is not consistently stimulatory.4. There are indications that the differential effect of sera from unilaterally nephrectomized and control animals is due to the presence of a stimulatory factor in the former rather than an inhibitor in the latter.5. Use ofthis culture system has confirmed the existence of a serum factor involved in compensatory renal growth.

Measurement of compensatory hyperplasia of the contralateral kidney: usefulness for differential diagnosis of fetal unilateral empty renal fossa

“…Although there have been several reports about the mechanism and physiology of compensatory renal hyperplasia5–10, there has been no report about the sonographic measurement or estimation of compensatory hyperplasia in fetal kidneys. Compensatory hyperplasia is usually determined when the length of the contralateral kidney is larger than the normal range in patients who have undergone a unilateral nephrectomy.…”

“…It is well known that compensatory hyperplasia of the remaining kidney usually occurs after unilateral nephrectomy, and there have been several reports describing its mechanism and physiology in animals5–10. Kaufman et al 11 and Celsi et al 12 reported that compensatory renal hyperplasia is age‐dependent, being more prevalent in young than in adult animals.…”

Does Renotropin Have a Role in the Pathogenesis of Hypertension?

“…Using renal fragments, we found that uninephrectomy sera compared to sham-operated sera enhanced renal ODC activity in 24 of 25 paired experi ments (+42.5% ± 9.0 (SEM), Ρ < .01. 43 Lyons and co workers 44 used hamster kidney cells in culture, Kanetake and Yamamoto 45 worked with primary rabbit kidney cell cultures and Hansen 46 examined primary rat kidney cultures to establish the existence of renotropin. Accordingly, all evidence points to the existence of a specific renal growth regulator.…”